Wa Alaikum Salam.
Following are some of the general tips, which I usually give for increasing fuel efficiency as well as general car maintenance.
Please check, and see, which apply in your case. Take remedial actions accordingly:
- Use OEM recommended Tyre Pressure (TP), and Best time to get TP checked is, when tires are cold and you are just about to start your journey.
- Do keep a check on wheel balancing and alignment, and rotate tyres after almost every ~10,000 Kms, in the pattern specified in the owners / users manual.
- Use of near to stock and OEM recommended tires specifications.
- Get your brakes serviced and engine tuned at every 10,000 kms (max.) or as and even required. Get spark plugs cleaned along with throttle body service. If plugs and brake pads are required to be replaced, use stock / OEM recommended plugs and brake pads, made in Japan, and replace them. Never use any other plugs and brake pads, they may compromise engine and safety, respectively. Clean Catalytic Converter, when required.
- Even if there are no check lights / warning lights, get your vehicle scanned through computer from any reputable shop, at least for once, for any / all fault codes.
- Get all the fluids / lubricants, CVT fluid, radiator coolant, etc. checked, and if they require top-up or replacement (depending on the situation), do it.
- Always use recommended Engine oil grade from some reputed brand, and change after regular intervals. Do not drag it for long.
- Always use genuine, OEM filters (Air, Oil, AC / Cabin, etc.) and try to keep air filter always clean. Its "lungs" for engine.
- Ensure that every product you use is 100% genuine and original.
- Let go of any additional weight in your car, boot compartment (Diggi), etc.
- Use fuel from well-renowned, respected fuel stations. Shell and Total fuel stations are recommended.
- Get Catalytic Converter serviced / replaced when choked, and you feel drop in power, pick, and fuel efficiency.
- Lastly, drive softly and carefully. Do not apply brakes harshly and accelerate / decelerate abruptly. Driving style matters the most.
I hope, by following above steps, you can get the best from your car. Thank you.